Cardiovascular effects of sex hormones.

The impact of sex steroids on the cardiovascular system is of considerable importance and a potential area for therapeutic intervention. In general, animal and human studies of the vascular effects of sex hormones have suggested that oestrogen is beneficial, certain progestins may negate these effects and androgens may be potentially deleterious. In this issue of Clinical Science, Tejera et al. [1] present data on differential constrictor responses to α # -adrenoceptor stimulation in thoracic aortic segments from oestrous phase and ovariectomized female rats and control and castrated male rats [1]. Endogenous oestrogen or androgen increased the contractile responses to clonidine. In all four groups an intact endothelium, predominately via endothelial-dependent NO release, significantly attenuated the constrictor responses ; this attenuation seemed to be greater in males. These results are of interest and add to the mosaic of data available on the cardiovascular effects of sex hormones. The effects of sex steroids are complex and are influenced by a variety of factors, including natural versus synthetic hormones, species, age, hormonal status, vessel preparation, endothelial function, disease state, lipid and coagulation factors.